In [1]:

    

import numpy as np
from scipy.sparse.csgraph import connected_components
from scipy.sparse import csr_matrix


    

In [2]:

    

l = [[0, 1, 1, 0, 0],
     [0, 0, 1, 0, 0],
     [0, 0, 0, 0, 0],
     [0, 0, 0, 0, 1],
     [0, 0, 0, 0, 0]]


    

In [3]:

    

# n, labels = connected_components(l)
# AttributeError: 'list' object has no attribute 'dtype'


    

In [4]:

    

a = np.array(l)
print(type(a))


    

    




<class 'numpy.ndarray'>

In [5]:

    

n, labels = connected_components(a)


    

In [6]:

    

print(n)


    

    




2

In [7]:

    

print(labels)


    

    




[0 0 0 1 1]

In [8]:

    

csr = csr_matrix(l)
print(csr)


    

    




  (0, 1)	1
  (0, 2)	1
  (1, 2)	1
  (3, 4)	1

In [9]:

    

print(type(csr))


    

    




<class 'scipy.sparse.csr.csr_matrix'>

In [10]:

    

n, labels = connected_components(csr)


    

In [11]:

    

print(n)


    

    




2

In [12]:

    

print(labels)


    

    




[0 0 0 1 1]

In [13]:

    

n = 5
d = [1, 1, 1, 1]
i = [0, 0, 1, 3]
j = [1, 2, 2, 4]


    

In [14]:

    

csr = csr_matrix((d, (i, j)), (n, n))
print(csr)


    

    




  (0, 1)	1
  (0, 2)	1
  (1, 2)	1
  (3, 4)	1

In [15]:

    

print(connected_components(csr, return_labels=False))


    

    




2

In [16]:

    

ld = [[0, 1, 1, 0, 0],
      [1, 0, 1, 0, 0],
      [0, 0, 0, 0, 0],
      [0, 0, 0, 0, 1],
      [0, 0, 0, 1, 0]]


    

In [17]:

    

n, labels = connected_components(csr_matrix(ld))


    

In [18]:

    

print(n)


    

    




2

In [19]:

    

print(labels)


    

    




[0 0 0 1 1]

In [20]:

    

n, labels = connected_components(csr_matrix(ld), connection='strong')


    

In [21]:

    

print(n)


    

    




3

In [22]:

    

print(labels)


    

    




[1 1 0 2 2]

In [23]:

    

ld2 = [[0, 1, 0, 0, 0],
       [0, 0, 1, 0, 0],
       [1, 0, 0, 0, 0],
       [0, 0, 0, 0, 1],
       [0, 0, 0, 1, 0]]


    

In [24]:

    

n, labels = connected_components(csr_matrix(ld2), connection='strong')


    

In [25]:

    

print(n)


    

    




2

In [26]:

    

print(labels)


    

    




[0 0 0 1 1]

In [27]:

    

n, labels = connected_components(csr_matrix(ld), directed=False, connection='strong')


    

In [28]:

    

print(n)


    

    




2

In [29]:

    

print(labels)


    

    




[0 0 0 1 1]

In [30]:

    

lw = [[0, 8, 5.2, 0, 0],
      [0, 0, 3, 0, 0],
      [0, 0, 0, 0, 0],
      [0, 0, 0, 0, -2],
      [0, 0, 0, 0, 0]]


    

In [31]:

    

n, labels = connected_components(csr_matrix(lw))


    

In [32]:

    

print(n)


    

    




2

In [33]:

    

print(labels)


    

    




[0 0 0 1 1]